pgsql: Revert pg_wal_replay_wait() stored procedure

Revert pg_wal_replay_wait() stored procedure

This commit reverts 3c5db1d6b0, and subsequent improvements and fixes
including 8036d73ae3, 867d396ccd, 3ac3ec580c, 0868d7ae70, 85b98b8d5a,
2520226c95, 014f9f34d2, e658038772, e1555645d7, 5035172e4a, 6cfebfe88b,
73da6b8d1b, and e546989a26.

The reason for reverting is a set of remaining issues.  Most notably, the
stored procedure appears to need more effort than the utility statement
to turn the backend into a "snapshot-less" state.  This makes an approach
to use stored procedures questionable.

Catversion is bumped.

Discussion: https://postgr.es/m/Zyhj2anOPRKtb0xW%40paquier.xyz

Branch
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master

Details
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https://git.postgresql.org/pg/commitdiff/3a7ae6b3d91e0d011dba1eb8a29e1836c6a33c75

Modified Files
--------------
doc/src/sgml/func.sgml                          | 170 ------------
src/backend/access/transam/Makefile             |   3 +-
src/backend/access/transam/meson.build          |   1 -
src/backend/access/transam/xact.c               |   6 -
src/backend/access/transam/xlog.c               |   7 -
src/backend/access/transam/xlogfuncs.c          | 116 +-------
src/backend/access/transam/xlogrecovery.c       |  11 -
src/backend/access/transam/xlogwait.c           | 337 ------------------------
src/backend/catalog/system_functions.sql        |   5 -
src/backend/lib/pairingheap.c                   |  18 +-
src/backend/storage/ipc/ipci.c                  |   3 -
src/backend/storage/lmgr/proc.c                 |   6 -
src/backend/tcop/pquery.c                       |   9 +-
src/backend/utils/activity/wait_event_names.txt |   2 -
src/include/access/xlogwait.h                   |  89 -------
src/include/catalog/catversion.h                |   2 +-
src/include/catalog/pg_proc.dat                 |  11 -
src/include/lib/pairingheap.h                   |   3 -
src/include/storage/lwlocklist.h                |   1 -
src/test/recovery/meson.build                   |   1 -
src/test/recovery/t/043_wal_replay_wait.pl      | 225 ----------------
src/tools/pgindent/typedefs.list                |   3 -
22 files changed, 9 insertions(+), 1020 deletions(-)